Overview: Red Eyes (Bloodshot Eyes)
Red eyes (bloodshot eyes) are a common condition characterized by abnormal reddening of the eyes.
The condition is painless and occurs due to swollen blood vessels near the surface of the eye. Most people experience red eyes from time to time.
However, red eyes should concern you if accompanied by eye pain, impaired vision, watering eyes, or a feeling of dryness in the eyes.
10 Reasons Why Your Eyes Might Be Red
Here are some causes of red eyes and how to prevent and treat them:
1. Dry Eye Syndrome
Dry eye syndrome refers to the inability of the eyes to produce adequate fluids (tears) to lubricate them.1
This condition may result from hormonal changes, underlying conditions, and certain medications such as antihistamines, birth control pills, and some painkillers.
Symptoms include:
- Stinging or burning eye
- Pain and redness in the eye
- Excessive tearing
- Eye fatigue
- Discomfort when reading or watching
- Blurry vision
- A feeling of an object in the eye
- Difficulty with nighttime driving
- Sensitivity to light
Treatment options:
An ophthalmologist may do tests to see whether a medical problem is the cause of your dry eyes.
Over-the-counter medicines such as artificial tears, gels, or ointments, may be beneficial in mild cases.
Depending on the severity of the condition, other treatments may include prescription eye drops and surgery.
You can also consider the lifestyle tips below:
- Get enough rest/sleep
- Hydrate by drinking plenty of water
- Avoid environmental triggers such as smoke, wind, and air conditioning
- Reduce your screen time
2. Eye Injury
Trauma to the eye can also cause redness. Something as simple as accidentally scratching your eye with a sharp fingernail can cause an eye injury.
Other causes of eye injuries include:
- Physical sports such as football, rugby, tennis, etc.
- Falls or car accidents
- Workplace hazards such as chemicals
- Physical eye strain that causes severe exertion (e.g., when coughing, sneezing, or vomiting)
When you hurt your eye, the blood vessels inside it expand and dilate. The dilated blood cells send blood and cells to the injured area to help restore it.
Developing a red eye as a result of an injury is also a warning that something is wrong with your eye.
The symptoms include:
- Pain and swelling in the eye
- Bruising and redness
- Bleeding, accompanied by small red or black spots in the eye
- Changes in vision
- Changes in the appearance of the eyes
3. Eye Allergies
Millions of Americans suffer from eye allergies, a condition also known as allergic conjunctivitis (pink eye). Mold, pollen, and pet dander are the most common airborne allergens.
Eye allergies may also be induced by reactions to certain cosmetics or eye drops containing allergy-causing ingredients.
When exposed to these allergens, cells in your eyes known as mast cells are triggered to release histamine and other substances that can result in inflammation:
The symptoms include:
- Red and irritated eyes
- Itchiness in the eyes
- Swollen eyelids
- Soreness or a burning sensation in the eyes
- Sensitivity to light
- Excessive tearing
- Blurred vision
- Swollen eyelids
Treatment options:
- Artificial tears to keep your eyes lubricated
- Oral decongestants such as phenylephrine (not to be confused with phenylephrine eye drops, which are used to dilate the pupils) and pseudoephedrine
- Oral antihistamines (watch out for dry eyes when taking these)2
- Mast cell stabilizers such as Bepreve
- Antihistamine eye drops such as olopatadine
- Corticosteroids to suppress inflammation
- NSAIDS such as diclofenac, ketorolac, or flurbiprofen sodium
4. Eyelid Styes
A stye (sty) is a tender lump or swelling along the lash line, close to the border of your eyelid.3
An internal stye, also known as a hordeolum, is a stye that develops on the inside of your eyelid.
Eyelid styes indicate bacterial infection and blockage of the eyelid oil glands.
While an internal or inner stye is less frequent than an external stye that occurs on the outer rim of the eyelid, both may result in complications due to its proximity to the eye.
This common eye infection typically clears up on its own. However, severe cases may require immediate medical attention.
Symptoms include:
- Swollen or droopy eyelids
- Pain and tenderness on the affected area
- Redness around the affected area
- A burning sensation
- Watery eyes
Treatment options:
A style normally lasts 3 to 7 days but can persist for a few weeks. Some home remedies to treat your stye include:
- Cleaning the affected eye
- Gentle eyelid massage with a warm compress
- Wear glasses and not contacts until you recover
- Keep your hands clean
Although most styes heal up quickly, don't be afraid to see your eye specialist for more advice. To help it heal quicker, your health care provider may prescribe an ointment or a medication.
5. Sunburned Eyes
Sunburned eyes or photokeratitis is caused by exposure to ultraviolet (UV) rays from the sun.
This condition is characterized by inflammation of the cornea (the clear front covering of your eye).
Overexposure to UV rays for extended periods can further lead to serious conditions such as cataracts, macular degeneration, or eyelid cancer.
Symptoms include:
- Gritty feeling in the eyes
- Headache
- Red eyes
- Swelling around the eyes
- Sensitivity to light
- Eye pain
- Pinpoint pupils (miosis)
Treatment options:
Photokeratitis typically goes away on its own in one to two days. Treatment for this disease usually focuses on alleviating symptoms so you may feel more at ease. It can worsen preexisting eye diseases.
Your doctor may prescribe pain relievers or antibiotic eye drops
Home remedies include:
- Cool compress
- Artificial tears to lubricate your eyes
- Skip your make-up until you heal
- Over-the-counter pain medication
- Sunglasses
6. Recent Eye Surgery
Eye surgeries such as LASIK can cause red eyes.4 This is because the procedure involves shifting, cutting, and shaping different components of your eyes (nerves, blood vessels, and cornea).
Although this will not impact your vision, the procedure may lead to temporary dry eyes or inflammation that may subside after a while.5
Symptoms include:
- Red or irritated eyes
- Stinging or burning sensation
- Feeling like there is something foreign in your eyes
- Excessive tearing
- Blurred vision (rare)
Treatment options:
Red eyes after eye surgery should not cause panic as it's part of the recovery process.
However, the following treatments can help alleviate the symptoms:
- Prescription eye drops or ointments6
- Artificial tears
- Wear protective devices until your eyes gain full recovery
- Drink a lot of water to stay hydrated
7. Glaucoma
Glaucoma is a group of eye disorders that damage the optic nerve, which is necessary for good vision.
This impairment is often caused by very high ocular pressure.
For individuals over the age of 60, glaucoma is one of the main causes of blindness.
Symptoms include:
- Bloodshot eyes
- Blind spots in vision
- Tunnel vision (loss of peripheral vision)
- Severe headache for acute glaucoma
- Eye pain
- Blurred vision
Treatment options:
Most therapies for glaucoma reduce intraocular pressure (IOP), which may be accomplished through:7
- Prescription eye drops
- Laser therapy
- Surgery
8. Endophthalmitis
Endophthalmitis is a serious eye problem caused by infection of the fluids or tissues of the eyeball. If not treated quickly, it can lead to blindness.
Symptoms often appear after a few days following the eye infection. Acute endophthalmitis is diagnosed when symptoms appear suddenly.
A slow progression of symptoms indicates chronic endophthalmitis. This occurs when certain bacteria or fungi invade the eye.
Symptoms include:
- Eye pain
- Redness in the eyes
- Yellow or greenish discharge
- Swollen or puffy eyes
- Vision problems
Treatment options:
- Injection of antifungals or antibiotics into the infected eye
- Systemic antifungals or antibiotics
- Steroids to reduce inflammation and swelling
- Vitrectomy surgery may be recommended for severe cases8
9. Smoking
Regular and long-term cigarette smokers may experience red eyes due to smoke irritation.
This is worse for those who wear contact lenses because smoking contributes to dry eyes.
Smoking marijuana can also cause red eyes. Tetrahydrocannabinol (THC), the psychoactive endocannabinoid ingredient in marijuana, tends to increase blood pressure.
Blood vessels and capillaries in the eyes dilate due to increased blood flow, resulting in bloodshot eyes.9
Symptoms include:
- Red and painful eyes
- Irritation from cigarette smoke
- Dry and itchy eyes due to toxic substances in cigarette smoke
- Increased eye pressure
Treatment options:
Red eyes from smoking marijuana often normalize after the effects wear off.
If red eyes are induced by irritation from cigarette smoke, the following remedies can help:
- Over-the-counter eye drops
- Decongestant eye drops in case of smoke allergies
- Regular eye exams
10. Exhaustion
Tired eyes are often bloodshot. This is because a lack of rest may reduce the amount of oxygen that reaches your eyes, causing blood vessels to dilate.
As a result, the eyes develop a reddish appearance.
Symptoms include:
- Dry eyes
- Redness in the eyes
- A feeling of heaviness in the eyes
Treatment option:
The best treatment for red eyes due to exhaustion is rest. Other options to consider include:
- Artificial tears to lubricate the eyes
- Cool compress to ease the discomfort
When Should You Worry About Red Eyes?
Most cases of red eyes improve with home remedies. However, if the symptoms persist, it may indicate a medical emergency.
Signs of a Medical Emergency
See your doctor immediately if your red eye is accompanied by:
- Severe eye pain
- Extreme light sensitivity
- Swelling in or around the eye
- Sudden vision changes
How to Get Rid of Red Eyes
There are various professional and home-based regimens for red eyes:
Professional Treatments
Professional treatments for red eyes include:
- Artificial tears. These are prescribed to help keep the eyes moisturized in the case of dry eyes.
- Vasoconstrictors (decongestants). They work by constricting the tiny blood vessels of the conjunctiva. Examples include tetrahydrozoline and naphazoline.
- Antihistamines. These are used to treat symptoms such as itching, redness, and pain. They can be prescribed or purchased over the counter.
Although redness relief drops are effective at clearing your eyes up, they do not resolve the condition causing the redness.
Additionally, they should be used conservatively since they constrict the blood vessels in your eye and are not ideal for your eye health if used regularly. It’s best to consult your eye doctor to receive proper treatment for your condition.
Home Remedies
Home treatments for red eyes include:
- Over-the-counter regimens such as artificial tears
- Avoiding triggers such as irritants (smoke, dust, and pollen)
- Over-the-counter antihistamine eye drops to ease inflammation
- General hygiene such as using clean towels and sleeping on clean bedding
- Cool compresses several times a day
How to Prevent Bloodshot Eyes
Here are some tips for preventing bloodshot eyes:
- Keep your hands clean and avoid touching your eyes with dirty hands
- Avoid going to bed with make-up
- Do not wear contact lenses longer than prescribed by your eye doctor
- Avoid eye-straining activities such as prolonged screen time
- Clean your contact lenses regularly
- Flush out your eyes with eye wash or water if you come into contact with contaminated substances
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